Ocean warmth hits record high

The world’s oceans were the “hottest ever recorded by humans” in 2021, according to a new academic study published Tuesday. 

The warming, caused by greenhouse gas emissions is yet another worrying sign of climate change. 

The study, published in the journal Advances in Atmospheric Science, stated that human-emitted greenhouse gases were the direct cause of an increase in the annual temperature of the world’s oceans, which were measured by the ocean heat content index. 

Scientists analyzed data from a buoy system in seven ocean basins that showed the top 2,000 meters of the oceans absorbed more than 227 excess zettajoules of energy compared to the average between 1981 and 2010. The 2021 reading broke the 2020 record by 14 zettajoules.

The oceans’ warming has rapidly increased since the 1980s. 

“The regional and global changes both reveal a robust and significant ocean warming since the late-1950s — the entirety of the reliable instrumental record,” the authors wrote.

The warming of the oceans, the scientists warned, “supercharge” extreme weather events such as storms, hurricanes and rainfall. 

“Warmer oceans supercharge the weather systems, creating more powerful storms and hurricanes, and increased precipitation. Warmer oceans lead to a warmer and moister atmosphere that promotes more intense rainfall in all storms, especially hurricanes, thereby increasing the risk of flooding.”

The Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific and Southern oceans, as well as the Mediterranean Sea, all showed “robust warming” in 2021, although annual variations are taken into account. But the Atlantic and Southern oceans were among those with “record-high heat content in 2021.”

Last year saw nine severe storms, four tropical cyclones and two flooding events that contributed to more than $100 billion in disaster recovery costs for the U.S, according to the National Oceanic and Atmospheric Administration. 

Hurricane Ida alone, which hit Louisiana in August, accounted for $60 billion of that total, becoming the fifth most expensive storm to hit the U.S.

The Environmental Protection Agency said “sea level has risen at a rate of roughly six-tenths of an inch per decade since 1880,” mostly along the Mid-Atlantic coast.

Sea level rise has led to the loss of land in Florida and New York, a trend expected to continue along the East Coast.

The Hill has reached out to the study’s authors for further comment.